Move the selection below the guide line

[meadX]

How to move the selection to the bottom of the reference line, the reference line is horizontal, the coordinates of the selection are random, how to move the selection up to the bottom of the reference line through the script? Thank you 

[Stephen_A_Marsh]

Just to be clear on terminology, by reference line, do you mean guide? As in View menu > New Guide?

If so, will there only be one guide – or at least only one horizontal guide?

[Stephen_A_Marsh · Accepted solution]

Perhaps something like this?

/*
Move Selection Top to Horizontal Guide Coordinate.jsx
v1.0 - 20th April 2023, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/move-the-selection-below-the-guide-line/td-p/13738648
*/

#target photoshop

var savedRuler = app.preferences.rulerUnits;
app.preferences.rulerUnits = Units.PIXELS;
if (activeDocument.guides.length === 1 && activeDocument.guides[0].direction == Direction.HORIZONTAL) {
    var hGuidePos = activeDocument.guides[0].coordinate.value;
    try {
        activeDocument.selection.bounds;
        var selTop = activeDocument.selection.bounds[1].value;
        var vMove = selTop - hGuidePos;
        moveSel(0, -vMove);
    } catch (e) {
        alert("There is no active selection!");
    }
} else {
    alert("There are multiple guides and or the guide is vertical!");
}
app.preferences.rulerUnits = savedRuler;

function moveSel(horizontal, vertical) {
    var s2t = function (s) {
        return app.stringIDToTypeID(s);
    };
    var descriptor = new ActionDescriptor();
    var descriptor2 = new ActionDescriptor();
    var reference = new ActionReference();
    reference.putProperty(s2t("channel"), s2t("selection"));
    descriptor.putReference(s2t("null"), reference);
    descriptor2.putUnitDouble(s2t("horizontal"), s2t("pixelsUnit"), horizontal);
    descriptor2.putUnitDouble(s2t("vertical"), s2t("pixelsUnit"), vertical);
    descriptor.putObject(s2t("to"), s2t("offset"), descriptor2);
    executeAction(s2t("move"), descriptor, DialogModes.NO);
}

[meadX]

Thank you for your help. Thank you